Agricultural Science 2021 Jamb Examination

The main objective of agriculture is food production since it ensures the availability of food for human consumption. Other objectives like income generation and employment are secondary outcomes of this primary goal.
Food production is essential for survival, national stability, and economic development, making it the most fundamental objective of agriculture.

Subsistence agriculture is mainly characterised by small farm holdings because it focuses on producing enough food for the farmer and their family. The farms are small, often managed manually, and with little or no use of machinery.
This form of farming contrasts with commercial agriculture, which involves large-scale production and advanced equipment.

Efficient pest control services help reduce food shortage by preventing crop destruction by pests. Pest infestation can drastically reduce yields and food availability.
By managing pests properly, farmers can increase productivity and ensure stable food supply throughout the year.

Population pressure is the most common factor affecting land use, as increasing human population leads to higher demand for housing, roads, and farmlands.
This pressure results in land fragmentation and conversion of agricultural lands to other uses, affecting productivity and land management practices.

Commercial agriculture relies more on mechanisation and adequate finance rather than employing large labour forces. The use of machines reduces human labour dependency.
Therefore, 'employment of large labour force' is not a reason for higher output, making it the exception among the listed options.

Tax is not a form of financial assistance; instead, it is a compulsory levy paid by individuals and organisations to the government. In contrast, loans, credits, and subsidies are forms of support given to farmers to improve productivity.
Thus, tax does not constitute any form of government aid to farmers.

Game reserves are designated areas where wild animals are protected and conserved in their natural habitats. Lions and elephants are wild animals typically found in game reserves.
Domesticated animals like cattle, camels, and chickens are not kept in game reserves, hence the correct group includes lions and elephants.

Branching in crops is not sensitive to daylength, unlike flowering, fruiting, and growth, which depend on photoperiodism. Photoperiodism influences when plants flower or bear fruits based on the duration of light exposure.
Branching, however, is more influenced by genetics and environmental conditions than daylength.

Rainwater becomes available to crops through root absorption, as plant roots take in water from the soil. The absorbed water supports physiological processes like photosynthesis and nutrient transport.
Evaporation and transpiration involve water loss, not absorption, making root absorption the correct process.

Slate is formed from shale through the process of metamorphism, which involves heat and pressure transforming the original sedimentary rock into a new structure.
This makes slate a metamorphic rock derived directly from shale, unlike marble (from limestone) or quartzite (from sandstone).